Hypercholesterolemia is known to be one of the prime risk factors for ischemic cardiovascular disease, such as arteriosclerosis. Bile acid sequestrants have been used to treat this condition; they seem to be moderately effective but they must be consumed in large quantities, i.e. several grams at a time and they are not very palatable.
MEVACOR.RTM. (lovastatin), now commercially available, is one of a group of very active antihypercholesterolemic agents that functions by limiting cholesterol biosynthesis by inhibiting the enzyme HMG-CoA reductase. In addition to the natural fermentation products, mevastatin and lovastatin, there are a variety of semi synthetic and totally synthetic analogs thereof.
The naturally occurring compounds and their semisynthetic analogs have the following general structural formulae: ##STR2## wherein: Z is hydrogen, C.sub.1-5 alkyl or C.sub.1-5 alkyl substituted with a member of the group consisting of phenyl, dimethylamino, or acetylamino; and
R.sub.1 is: ##STR3## wherein Q is ##STR4## R.sub.3 is H or OH; and R.sub.2 is hydrogen or methyl; and a, b, c, and d represent optional double bonds, especially where b and d represent double bonds or a, b, c, and d are all single bonds.
U.S. Pat. No. 4,517,373 discloses semi-synthetic hydroxy containing compounds represented by the above general formula wherein R.sub.1 is ##STR5##
U.S. Pat. Nos. 4,537,859 and 4,448,979 also disclose semisynthetic hydroxy-containing compounds represented by the above general formula wherein R.sub.1 is ##STR6##
These compounds are prepared by the action of certain microorganisms on the corresponding non-hydroxylated substrates. One such organism described in U.S. Pat. No. 4,537,859 is of the genus Nocardia.
U.S. Pat. No. 4,376,863 discloses a fermentation product, isolated after cultivation of a microorganism belonging to the genus Aspergillus, which has a hydroxy containing butyryloxy side chain and is represented by the above general formula
wherein R.sub.1 is ##STR7##
Japanese unexamined patent application J59-122,483-A discloses a semisynthetic hydroxy containing compound represented by the above general formula wherein R.sub.1 is ##STR8##